The following correction was printed in the Guardian's Corrections and clarifications column, Monday March 27 In the below article, we said that Winifred Cornwell was one of the first two women medical students to graduate from St Mary's Hospital, London, in the 1950s. In fact, there was a much earlier group of graduates. The hospital archivist writes: "In 1915, students from the London School of Medicine for Women were admitted to do their clinical studies at St Mary's as a wartime measure since there was a shortage of male medical students. This arrangement lasted until 1924 when St Mary's reverted to being a male school after protests from the men about the feminisation of the school and the consequent emasculation of the rugby team. Only after the second world war in 1948 were all the London medical schools, including St Mary's, compelled to take a quota of women students."

Dr Winifred Cornwell, who has died aged 80, was one of the first two women medical students to graduate from St Mary's hospital, London, and was consultant anaesthetist at the London Chest hospital from 1971 to 1991, a period during which she played a pivotal part in establishing the unit's reputation as the country's premier centre for the treatment of coronary artery disease.

She will be particularly remembered for taking a lead in the plans that led to the opening of the unit's new state-of-the-art, 10-bed cardiac intensive care unit in the mid-1980s. This enabled surgeons at the London Chest not only to increase the unit's case load but also to tackle the most serious disease, armed with the knowledge that clinicians overseeing the aftercare of their patients would be doing so with access to the most sophisticated monitoring and ventilation equipment available.

Cornwell was born in Bere Ferrers, Devon, the daughter of a blacksmith. When she was young the family moved to Faringdon in Berkshire, where she won a scholarship to Faringdon grammar school. She then went to medical school at University College London, and subsequently to St Mary's. After qualifying, she chose anaesthesia as her speciality and in 1954 passed the diploma in anaesthesia. In 1953 she married a fellow student, John Cornwell, who, in 1957, took a post with the medical division of Shell. Together they travelled to Trinidad, Nigeria and Indonesia, where she did occasional medical work, though not in an official capacity.

On returning to England, Cornwell took up her professional career in anaesthesia again. In 1969 she obtained the fellowship of the Faculty of Anaesthetists, now the Royal College, and then went to the London Chest hospital, where she became the first full-time woman consultant. She set about imposing on others the exacting standards that she always demanded of herself. Colleagues emphasise that it was her leadership and enterprise, combined with those of John Wright and Fred Alladine, that were instrumental in shaping the London Chest into the unit that it became.

It was perhaps her work on the intensive care unit that absorbed her most. It was always her wish that patients and colleagues should have the benefit of the best medical resources. To this end she set up a fund, into which she paid the earnings from her private practice, for the purpose of obtaining for the unit otherwise unaffordable equipment.

After retirement in 1991, she became an expert bridge player. She developed a wide circle of friends in this and in the sphere of musical appreciation.

She was always immaculately dressed, which led to her being known affectionately as "the duchess". She had the great gift of being able to laugh at herself, and found it amusing when young doctors, having watched her park her car, declared that it had the look of being abandoned rather than parked. Her professional legacy is that she provided guidance and friendship for a new generation of consultant anaesthetists.

Her two marriages were dissolved. She was an extremely private person who never boasted of her achievements.

· Winifred Betty Cornwell, doctor, born October 7 1925; died January 6 2006